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REVIEWED PLN_RESUB1 BLD2021-0591+Enviro.Report+7.16.2021_3.22.44_PM+2305999CEDAROCK CONSULTANTS, INC. Environmental Consulting RESU B BLD2021-0591 Jul 16 2021 CITY OFEDMONDS CRITICAL AREAS REPORT DEVELOPMENT SERVICES DEPARTMENT GREY SEA LLC RESIDENCE REDEVELOPMENT 729 Laurel Street Edmonds Washington 98020 (Parcel # 9253900435) Prepared by: Cedarock Consultants, Inc. 19609 244th Avenue NE Woodinville, Washington 98077 Prepared for: Grey Sea, LLC 66 S. Hanford St, Suite 300 Seattle, Washington 98134 July 16, 2021 (rev #1) 19609 244" AVENUE NE • WOODINVILLE, WA 98077 • 425/788-0961 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report TABLE OF CONTENTS Page 1.0 INTRODUCTION................................................................................................................1 1.1 Project Description........................................................................................................1 1.2 Purpose of this Report..................................................................................................1 1.3 Report Author...............................................................................................................1 2.0 EXISTING CONDITIONS.....................................................................................................1 2.1 Stream...........................................................................................................................1 2.2 Stream Buffer................................................................................................................2 2.3 Species of Local Importance.........................................................................................3 3.0 PROJECT EFFECTS ON CRITICAL AREAS.............................................................................. 3 3.1 Stream...........................................................................................................................4 3.2 Species of Local Importance.........................................................................................4 4.0 MITIGATION.....................................................................................................................5 4.1 Impact Avoidance..........................................................................................................5 4.2 Impact Minimization.....................................................................................................5 4.3 Compensatory Mitigation.............................................................................................5 5.0 VEGETATION MAINTENANCE............................................................................................5 6.0 VEGETATION MONITORING..............................................................................................6 7.0 CONTINGENCY PLAN........................................................................................................ 6 8.0 MITIGATION COST ESTIMATE........................................................................................... 7 9.0 CODE COMPLIANCE.......................................................................................................... 7 LIST OF FIGURES Figure 1. Grey Sea LLC property in Edmonds..................................................................................2 Figure 2. Existing stream buffer conditions....................................................................................3 LIST OF TABLES Table 1. Stream Buffer and Setback Changes under the Proposed Action ................................... 4 APPENDICES Development Proposal Site Plan Mitigation Planting Plan and Details Bond Cost Estimate REPORT AUTHOR: This report was prepared by Carl Hadley, a professional aquatic biologist with over 30 years of experience evaluating effects of changing land use on aquatic habitat. Mr. Hadley is the principal biologist with Cedarock Consultants, Inc. July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page i Grey Sea Redevelopment Edmonds, Washington Critical Areas Report 1.0 INTRODUCTION 1.1 Project Description An existing home located at 729 Laurel Street in Edmonds (Figure 1) will be extensively remodeled using the existing foundation. The northern portion of the site is encumbered by a stream buffer with the stream itself located off -site. The existing house lies partially within the stream buffer and setback area. Under the proposed action the house will be expanded slightly towards the stream but will do so in place of the existing house, deck, concrete patio and staircase that are to be removed. As mitigation, overall structure, driveway, and patio within both the stream buffer and the setback will be significantly reduced. 390 sf of stream buffer will be enhanced with new native plantings to include two trees. A third tree will be planted elsewhere on site. 1.2 Purpose of this Report A Critical Areas Determination (CRA2020-0125) completed by the City' noted the presence of the off -site stream and determined that a Critical Areas Study would be required. No other critical areas were noted. This report was prepared to evaluate environmental effects of the proposed project on the stream and stream buffer. Mitigation is proposed where necessary to offset adverse impacts. 1.3 Report Author This report was prepared by Carl Hadley, a professional habitat biologist with over 30 years of experience in western Washington. 2.0 EXISTING CONDITIONS The site was visited by Carl Hadley on March 3, 2021 to examine existing conditions and review potential changes proposed under the redevelopment plan. The creek was observed from over the fence, a distance of about 10 feet. 2.1 Stream A small watercourse runs from east to west across the neighbor's property to the north. The channel is less than two feet wide and runs down a roughly 20 percent slope. It appears to have been highly modified with bank protection and possible channelization in places. The City has 1 City of Edmonds. 2020. Critical Areas Determination (CRA2020-0125) - 729 Laurel St. Report provided by Michele Szafran, City of Edmonds Planning Division to Grey Sea LLC. Sept. 2, 2020. July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 1 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report classified it as a Type Np water with a 50-foot buffer. We saw no evidence to contradict this assessment. Figure 1. Grey Sea LLC property in Edmonds. 2.2 Stream Buffer Much of the area immediately adjacent to the stream appears to be managed by the neighbors as part of their yard and contains little vegetation. A line of what appears to be old, highly managed Pyramidalis (Thuja sp.) and five western redcedar are present off -site between the July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 2 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report stream and the subject property (Figure 2). These trees provide almost complete visual separation between the site and the stream. Some of the trees are in poor shape and riddled with invasive ivy species. There are no trees or other significant vegetation within the stream buffer or setback on the subject property. A few landscaping shrubs (Japanese maple and juniper) are scattered around but most of the buffer area is covered with concrete and asphalt. Groundcover in the few dirt -covered areas consist of periwinkle (Vinca) and weedy grasses. There are no functional habitat features on the subject property. Figure 2. Existing stream buffer conditions looking north at west side (left) and east side (right) of the property. 2.3 Species of Local Importance The wildlife habitat review consisted of a site -specific survey and consultation with the Washington Department of Fish and Wildlife database'. The site and surrounding lands have been developed mostly as moderate -density single -unit residential housing (Figure 2). Some suitable wildlife habitat for terrestrial and avian species is found in the area, in particular within a few larger trees scattered around the neighborhood. However, overall wildlife habitat quality has been significantly modified by past clearing, fragmentation, and introduction of non-native landscaping species (e.g. English ivy, English holly, Himalayan blackberry, and turf grasses). The highly pruned cedars and scattered landscaping shrubs found on the site provide very little wildlife habitat. No sensitive habitat or species (other than the creek) has been reported within 200-feet of the site. 3.0 PROJECT EFFECTS ON CRITICAL AREAS Critical areas are defined in the City of Edmonds under Chapter 30 of the development code. They include wetlands, critical aquifer recharge areas, frequently flooded areas, geologically hazardous areas, and fish and wildlife habitat conservation areas (and buffers). Existing conditions fish and wildlife habitat conservation areas on or near the site are described in Section 2.0 of this report. This section describes any actions that will be taken within or near the critical area and any proposed changes to the functions or values that will occur. Critical Area functions ' Washington Department of Fish and Wildlife. 2021. Priority habitat and species map. July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 3 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report and values for fish and wildlife species are based on WDFW guidelines' and other best available science4. 3.1 Stream The Type Np stream is located off -site. The stream channel will not be directly affected in any way. However, roughly the northern third of the site is encompassed by the 50-foot stream buffer and about half of the site is covered by the combination of the buffer and 15-foot setback. The entire site within the buffer and setback has been highly modified having been completely cleared and heavily graded when the site was originally developed in 1961. A house, above ground wooden deck, concrete patio under the deck, and paved parking area were all installed during this period. Development within the stream buffer and setback will be mitigated in several ways. The existing deck, concrete patio, and much of the paved parking area will be eliminated and replaced with pervious surfaces including lawn, garden, and native planting areas. Overall, the area of impervious surface within the stream buffer will be reduced by 949 sf as shown in Table 1. Table 1. Stream Buffer and Setback Changes under the Proposed Action --- 50' Existing Stream Buffer --- Proposed Change --- 15' Existing Buffer Setback --- Proposed Change Total Change Condition Structure/Asphalt/Concrete 1,814 865 -949 1,151 1,141 -10 -959 Garden/Weeds/Gravel/Rockery 1,444 2,003 559 340 350 10 569 Native Vegetation 0 390 390 0 0 0 i 390 Because no existing native riparian vegetation will be disturbed, the only impact will be to previously disturbed areas (mainly concrete and asphalt). The area of impervious surface will be significantly reduced. With additional native plants and rainwater infiltration (reduced runoff), the net benefit to the stream is expected to be positive. 3.2 Species of Local Importance All new development will take place within areas of existing structure and impervious surface. No native vegetation or any significant trees will be removed, and no new human activities will be introduced to the area. New native vegetation to include three new trees will be planted on the site. Overall, there will some short-term disturbance during construction, but significant long-term improvements to upland wildlife habitat. 3 Knutson, K. L. and V. L. Naef. 1997. Management recommendations for Washington's priority habitats: riparian. Washington Department of Fish and Wildlife, Olympia, WA. 181p. 4 For example, see Citations of Recommended Sources of Best Available Science for Designating and Protecting Critical Areas. 2002. Washington State Office of Community Development, Olympia, WA. and City of Bellevue's 2005 Best Available Science (BAS) Review (Herrera 2005). July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 4 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report 4.0 MITIGATION Chapter 23.40.110 requires mitigation for all impacts to critical areas and buffers. Mitigation sequencing is also required as described in Chapter 23.40.120. The primary means of mitigation for redevelopment of this lot has been avoidance of new disturbance by working only in the existing building footprint. Compensatory mitigation in the form of reduction of impervious surfaces and native plantings are proposed by the applicant. 4.1 Impact Avoidance The following actions are proposed to avoid impacts to critical areas: • No disturbance is proposed to the stream channel. • No new land disturbance is proposed, all work is proposed within the existing building footprint and concrete patio under the deck. • No large trees or native vegetation will be disturbed. 4.2 Impact Minimization The following actions are proposed to minimize impacts: • The existing house footprint for the most part will be reused. Land disturbance will be minimal with most of the new section of house supported above the ground on columns. 4.3 Compensatory Mitigation The following actions are proposed to improve habitat functions: • An existing concrete patio, asphalt driveway, and large deck (949 sf) will be removed from within the stream buffer. • New native vegetation to include two native trees will be planted within 20-feet of the stream. • One additional native tree will be planted elsewhere on the site. 5.0 VEGETATION MAINTENANCE Re-establishing native vegetation in the area adjacent to the creek is the goal of this maintenance plan. Activities required to maintain new plantings include initial watering of the new plants, and periodic removal of non-native vegetation that could damage or shade out the young plants. • New plantings shall be periodically watered (once or twice per month) from May through mid -October during the first season. A potable water source is available for this use. • Maintenance, to include removal of non-native species from the mitigation planting area shall be completed at minimum twice each year. • The use of herbicides and pesticides is prohibited unless given written permission by the City of Edmonds. • All work shall be performed by hand with the lightest possible equipment. July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 5 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report 6.0 VEGETATION MONITORING Due to the small size and uncomplicated nature of the proposed planting project the plantings shall be self -maintained and self -monitored by the homeowner for a period of five years. Reports shall be provided to the City in Years 1, 3, and 5 after planting. Vegetation monitoring shall consist of plant inspection to determine the health and vigor of each planted tree. All replacement plants shall be inspected once a year for five years to determine the health of each specimen. Dead or dying plants shall be replaced the following fall. Plant species substitutions may be made if site conditions are believed responsible for plant mortality. Replacement species must be approved by the City. Monitoring reports shall be submitted to the City of Edmonds, Attn: Environmental Planning Manager by October 31st in Years 1, 3, and 5 after planting. Photos showing the planting area shall be included in the monitoring reports to document conditions. The following schedule and performance standards apply and will be evaluated in the report for each year: Year 1 (from date of Dlant installation • 100% survival of all installed plants and/or replanting in following dormant season to reestablish 100% of original plantings. • Less than 10% coverage of invasive plants in planting area. Year 3 (from date of plant installation) • At least 85% survival of all installed material (100% of trees). • At least 35% coverage of the planting area by native plants. • Less than 5% coverage of planting area by invasive species or non-native/ornamental vegetation. Year 5 (from date of Dlant installation • At least 85% survival of all installed material (100% of trees) • At least 70% coverage of the planting area by native plants • Less than 5% coverage by invasive species or non-native/ornamental vegetation. 7.0 CONTINGENCY PLAN A contingency plan would be implemented if necessary. Contingency plans would be developed based on the specific failure to meet success standards described in Section 7 of this plan. Contingency plans could include additional plant installation and plant substitutions including type, size, and location. If monitoring results indicate that any of the performance standards are not being met, it may be necessary to implement all or part of a contingency plan. Careful attention to detail and site maintenance is essential in ensuring that problems do not arise. Should any of the site fail to July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 6 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report meet success criteria, a contingency plan will be developed and implemented with City approval. Such plans are prepared on a case -by -case basis to reflect the failed mitigation characteristics. Contingency/maintenance activities may include: • Engineering plan revisions for drainage, slope protection, etc. • Replacing all plants lost to browsing, drought, or disease, as necessary. • Replacing any plant species with a 20 percent or greater mortality rate with the same species or similar species approved by the City Biologist. • Irrigating the planting area only as necessary during dry weather if plants appear to be too dry, with a minimal quantity of water. • Streambank erosion protection measures. • Removing trash or other undesirable debris from the buffer area as necessary. 8.0 MITIGATION COST ESTIMATE A cost estimate for the mitigation planting, maintenance, and monitoring based on the King County spreadsheet updated to 2021 prices is $6,930. Details are provided in the appendix. 9.0 CODE COMPLIANCE The proposed redevelopment project will be completed under Chapter 23.90.040.D.5. - Development Proposals within the Footprint of Existing Development. This section requires certain conditions are met. We have listed the conditions below and provided a description of how the project was designed to meet each one. a. The footprint of existing development was legally established, and is consistent with the definition provided in ECDC 23.40.005; The footprint of the existing development as described in ECDC 23.40.005 was legally established and has been in place since 1961. b. The proposed development within the footprint of existing development is sited as far away from the stream edge as is feasible; Various development options were reviewed and the current proposal slightly reduces the development footprint within the buffer while maintaining the rest of the structure in the historic footprint. This gets the structure slightly further from the stream edge. There is no other reasonable alternative that would provide additional stream buffer function. c. As part of the development proposal, opportunities to reduce the footprint of existing development are implemented where such reduction would increase the buffer width adjacent to the stream and not represent an undue burden given the scale of the proposed development; July 16, 2021 CEDAROCK CONSULTANTS, INC. Grey Sea CAR071621.docx Page 7 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report The current proposal provides significant development reduction in both the stream buffer and stream buffer setback. Altogether the quantity of impervious surface will be reduced by 1,158 sf near the stream. This area will be converted to landscaping and gardening area for the homeowners. d. The proposed development includes enhancement to the adjacent remaining stream buffer in order to improve functions degraded by previous development; Initial development of the lot included large, paved areas of the stream buffer for use as patio and parking. This resulted in greatly increasing stormwater runoff rates from the site. Under the proposed action 1,158 sf of the buffer and setback will be returned to native soil and maintained that way in perpetuity. This will significantly increase infiltration capacity and reduce runoff rates from the site. e. Enhancement is provided as buffer enhancement for an equivalent area of the footprint of the occurring in stream buffer; and There is a total of 210.3 sf of proposed development in the stream buffer, all within the footprint of existing development. This is being mitigated by removing 1,057 sf of existing imperious surface from the buffer, thereby improving buffer function (primarily stormwater infiltration and water quality enhancement). This provides an enhancement ratio of 5:1, significantly exceeding the 1:1 requirement. f. Impacts from temporary disturbances within the stream buffer shall be addressed through use of best management plans and buffer enhancement plantings during and following construction of the allowed alteration. While work will occur within the stream buffer as part of the restoration process, no temporary construction disturbance to any natural habitat within the stream buffer is proposed. All areas of the buffer in which work will occur are currently considered highly disturbed (i.e. paved). There will be no temporal habitat loss associated with this project. The only work within this area will be restoration of existing areas of disturbance to a more natural state. July 16, 2021 Grey Sea CAR 071621.docx CEDAROCK CONSULTANTS, INC. Page 8 Grey Sea Redevelopment Edmonds, Washington Critical Areas Report NOT TO SCALE July 16, 2021 Grey Sea CAR 071621.docx CEDAROCK CONSULTANTS, INC. Page 9 OFF -SITE' TYPE Np STREAM MITIGATION PLANTING MITIGATION - IMPERVIOUS SURFACE / 390 SF STRUCTURE REDUCTION BUFFER 1,057 SF : SETBACK 9 SF 37 EXISTING STRUCTURE EXISTING PAVEMENT 24' 50-FOOT STREAM BUFFER PROPOSED STRUCTURE PROPOSED 15-FOOT EAVE 0 SETBACK 0 0 0 0 0❑ ° ❑ Scale 1" = 16' 1 F MITIGATION PROPOSAL APPLICANT: Grey Sea LLC 729 Laurel Street Edmonds, Washington 98020 July 16, 2021 1 Sheet 1 of 3 PLANTING DETAILS The following plant counts are based on 390 sf to be planted near the off -site creek as shown on Sheet 1. • Three trees to be planted per ECDC 23.10.060.C.5 • Shrubs to be planted 5' o.c.: at 25 sf per shrub = 16 shrubs • Groundcovers/bulbs to be planted as infill = 115 FRONT YARD j PROPOSED EAVE O O O O O l� l� l� 0 PLANT NAME AND SPECIES SIZE # GROUNDCOVERS - 929 total K KINNIKINNIK (Arctostaphylos uva-ursi) 4" 15 CAMAS (Camassia quamash) Bulbs 100 SHRUBS - 149 total DEER FERN (Blechnum spicant) 1-GAL 2 SWORD FERN (Polystichum munitum) 1-GAL 4 EVERGREEN HUCKLEBERRY (Vaccinium ovatum) 1-GAL 2 MANZANITA (Arctostaphylos sp.) 1-GAL 2 OREGON BOX (Paxistima myrsinites) 1-GAL 2 PACIFIC RHODODENDRON (R. macrophylum) 2-GAL 2 RED FLOWERING CURRANT (Ribessanguineum) 1-GAL 2 TREES - 3 total VINE MAPLE (Acer circinatum) 5-GAL 1 SHORE PINE (Pinus contorta) 5-GAL 1 CASCARA BUCKTHORN (Rhamnus purshiana) 5-GAL 1 STREAM BUFFER 3 7' I \ C \ K K K K 24 K CAMAS 0 PLANTING DETAILS PLANT INSTALLATION 1. Plant materials shall be nursery grown or collected in the Puget Sound area. Plants shall be normal in pattern of growth, healthy, well —branched, vigorous, with well —developed root systems, and free of pests and diseases. Damaged, diseased, pest —infested, scraped, bruised, dried out, burned, broken, or defective plants will be rejected. 2. If selected species are not available or desirable, then similar species may be substituted with approval from owner and City of Edmonds. 3. Planting shall occur during the cool season (September 15 through March 15). 4. Landscaper shall examine soils in the area to determine suitability for selected plants. New topsoil or compost amendment shall be added to a depth of 12" where necessary to support plants. 5. Immediately after planting, plants shall be watered to saturation. 6. Planting locations shown on the plan are approximate. Actual planting locations shall be field determined at time of planting by landscape architect or biologist. If significant changes are made, an as —built plan shall be prepared and submitted to the City of Edmonds. A minimum of 390 sf of new plantings shall be installed and maintained. 7. Provide good quality landscape mulch around all shrubs. LANDSCAPING MAINTENANCE 1. Controlling any non—native species and re—establishing native vegetation are the primary goals of this maintenance plan. Activities required to maintain new plantings include initial watering of the new plants, and periodic removal of non—native vegetation (weeding) within the planting area. 2. New plantings shall be watered from May through mid —October during the first season. A temporary irrigation system is allowed. A potable water source is available for this use. 3. Due to the aggressively invasive habit of many non—native species in the area, and the existence of nearby seed sources, control efforts shall be completed for five years following initial plant installation. Establishment of native plantings over the five year time period will create a well established native habitat lessening the chance for non—native vegetation invasion. 4. The control of invasive weeds (competing grasses and herbs) shall be mechanically provided throughout the planting area at a minimum of twice per year, or more should additional weeding be deemed necessary. The optimal season for weed control occurs in April thru September. The use of herbicides and pesticides shall be avoided. All work shall be performed by hand with the lightest possible equipment. MONITORING 1) Compliance monitoring consists of evaluating the plants immediately after plant installation. The objective is to verify that all design features, as agreed to in the plans, have been correctly and fully implemented, and that any changes made in the field are consistent with the intent of the design. Evaluation of the planting areas after restoration will be done by the homeowner. A brief compliance report will be prepared describing final plant counts and noting any substitutions or movement of plants when compared to the design. Rationale for changes shall be provided. Three photo points will be established giving complete coverage of the buffer area. 2) Long Term Monitoring — New plantings will be monitored in late summer in years one, three, and five after plant installation. Monitoring will be conducted by the homeowner to quantify the survival, relative health and growth of plant material. An annual monitoring report submitted to the City following each years monitoring visit will describe and quantify the status of the mitigation and provide the three photos from the same locations as the compliance report. Vegetation monitoring will consist of plant inspection to determine the health and vigor of the installation. All planted material in the buffer will be inspected during each monitoring visit to determine the level of survival of the installation. Each shrub and tree will be rated either as dead, dying, or healthy. Dead or dying material will be replaced the following fall unless plant crowding is believed to be a problem. Plant species substitutions may be made if site conditions are believed responsible for plant mortality. Replacement plants must be approved by the City. Volunteer native, non—invasive species will be included as acceptable components of the mitigation project. Ground covers will be rated as percent ground coverage for each of the major areas covered with these species. At least three photo points will be established giving complete coverage of the buffer area. Photos will be taken at each point during every monitoring visit and submitted as part of the annual monitoring report. PERFORMANCE STANDARDS Year 1 (from date of plant installation) • 100% survival of all installed plants and/or replanting in following dormant season to reestablish 100% of original plantings • Less than 10% coverage of invasive plants in planting area. Year 3 (from date of plant installation) • At least 85% survival of all installed material (100% of trees) • At least 35% coverage of the planting area by native plants • Less than 5% coverage of planting area by invasive species or non—native/ornamental vegetation. Year 5 (from date of plant installation) • At least 85% survival of all installed material (100% of trees) • At least 70% coverage of the planting area by native plants • Less than 5% coverage by invasive species or non—native/ornamental vegetation. Critical Areas Mitigation Bond Quantity Worksheet Project Name: Grey Sea LLC Date: 07/16/2021 Prepared by: Carl Hadley Project Number: Project Description: House Mitigation Buffer Planting Location: 729 Laurel Street Applicant: Grey Sea LLC Phone: PLANT MATERIALS (includes labor cost for plant installation) Type I Unit Pricel Unitl Quantityl Descriptioni Cost PLANTS: Bulbs $1.00 Each 100 $ 100.00 PLANTS: Potted, 4" diameter, medium $5.00 Each 15 $ 75.00 PLANTS: Container,1 gallon, medium soil $11.50 Each 14 $ 161.00 PLANTS: Container, 2 gallon, medium soil $20.001 Each 1 2 $ 40.00 PLANTS: Container, 5 gallon, medium soil $36.00 Each 3 $ 108.00 TOTAL $ 484.00 INSTALLATION COSTS ( LABOR, EQUIPMENT, & OVERHEAD) Type I Unit Price Unit Quantity Description FCost Compost, vegetable, delivered and spread $37.88 CY 1.00 $ 37.88 installation) $40.00 HR 6.00 $ 240.00 Labor: Consultant, supervising $55.00 HR 1.00 $ 55.00 Watering, 1" of water, 50' soaker hose 1 $3.621 MSFI 1.001 $ 3.62 Irrigation - temporary 1 $3,000.00 Acre 0.01 $ 26.10 77 TOTAL $ 362.60 ITEMS of Construction Unit Quantity Description Cost Mobilization 10% 1 1 $ 84.66 Contingency 30% 1 1 $ 253.98 TOTAL $ 338.64 MAINTENANCE AND MONITORING Less than 1,000 sf and buffer only Maintenance, annual (by owner or consultant) $1.10 SF 390.00 For Tive years $ 2,145.00 Monitoring $720 Each 5.00 $ 3,600.00 TOTAL $ 5,745.00 Total $6 930